diff --git a/src/main.rs b/src/main.rs
index 06fab3e..294b626 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,40 +3,26 @@ mod list;
 
 struct Solution {}
 impl Solution {
-    pub fn min_insertions(s: String) -> i32 {
-        let s = s.as_bytes();
-        let mut emp_s = vec![];
-        let mut ans = 0;
-        let mut i = 0;
-        while i < s.len() {
-            if s[i] == b'(' {
-                emp_s.push(b'(');
-            } else {
-                if i + 1 >= s.len() || s[i + 1] != b')' {
-                    ans += 1;
-                } else {
-                    i += 1;
-                }
-                emp_s.push(b')');
-            }
-            i += 1;
-        }
+    pub fn remove_outer_parentheses(s: String) -> String {
         let mut cnt = 0;
-        for (i, c) in emp_s.iter().enumerate() {
-            if *c == b'(' {
-                if cnt < 0 {
-                    ans += -cnt;
-                    cnt = 0;
+        let mut ans = vec![];
+        for c in s.chars() {
+            if c == '(' {
+                if cnt != 0 {
+                    ans.push(c);
                 }
                 cnt += 1;
             } else {
                 cnt -= 1;
+                if cnt != 0 {
+                    ans.push(c);
+                }
             }
         }
-        if cnt < 0 { ans - cnt } else { ans + cnt * 2 }
+        ans.iter().collect()
     }
 }
 
 fn main() {
-    println!("{:?}", Solution::min_insertions("()()))((".to_string()));
+    println!("{:?}", Solution::remove_outer_parentheses("(()())(())(()(()))".to_string()));
 }